Sleep apnea device to positively block exhaling and method of use

ABSTRACT

Nasal cannula devices for insertion in a sleep apnea patient&#39;s nasal passages, the device is formed with through air-flow passages and having circular membranes operative upon inhaling by the patient to open for free flow of air into the nasal passages and, further, operative upon exhalation by the patient to block expiration by the patient. 
     The invention further includes a method of providing for free flow of air into a patient&#39;s nasal passages upon inhaling and blocking air-flow form the nasal passages during exhalation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. Ser. No. 14/465,308 filed Aug. 21, 20143, the entire contents of which are incorporated by reference herein and priority is claimed thereto.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to sleep apnea devices and particularly to the type inserted in the nasal passages to control exhaling by the patient.

2. Description of the Related Art

Apnea is a Greek term meaning “without breath”. Simply stated apnea means cessation to breathing, something that may lead to decreased oxygen saturation (hypoxia) and an accumulation of carbon dioxide in the bloodstream. Hundreds of millions of patients are afflicted with sleep apnea, a dangerous condition which can lead to sleep deprivation and the consequent unhealthy existence and even death.

There are three types of sleep apnea: Obstructive, Central and mixed. Obstructive sleep apnea is the more common of the two. Obstructive Sleep Apnea can occur as repetitive episodes of complete or partial upper airway blockage during sleep. During an apnea episode, the diaphragm and chest muscles work harder as the pressure increases to open the airway. Breathing frequently resumes with a loud gasp or body jerk. These episodes can interfere with sound sleep, reduce the flow of oxygen to vital organs, and cause heart rhythm irregularities.

In Central Sleep Apnea, the airway is not blocked but the brain fails to signal the muscles to read due to instability in the respiratory center. This affliction is not addressed by the present invention.

Mixed sleep apnea is combination of both obstructive and central.

While Obstructive Sleep Apnea (OSA) is commonly associated with obesity and the male gender, it affects a broad cross-section of the population. Other risk factors include habitual snoring, which is often a precursor of more serious upper respiratory disorders such as Obstructive Sleep Apnea. In fact, results from a recent study indicate that 1 in 3 men and 1 in 5 women who snore habitually suffer from some degree of Obstructive Sleep Apnea.

Symptoms of OSA may be recognized by the bed partner or the patient him or herself. The most common symptoms include snoring, daytime sleepiness or fatigue, restlessness during sleep, sudden awakening with a sensation of gasping or choking, dry mouth or sore throat upon awakening, intellectual impairment, such as trouble concentrating, forgetfulness or irritability, night sweats, sexual dysfunction and headaches.

Left untreated sleep apnea can result in a number of health problems including hypertension, stroke, arrhythmias, cardiomyopathy (enlargement of the muscle tissue of the heart), congenital heart failure, diabetes, and heart attacks. In addition, the untreated sleep apnea may be responsible for job impairment, work related accidents, and motor vehicle crashes as well as academic underachievement in children and adolescents. The risks are significantly increased for those suffering from obesity, chronic lung disease, cardiac disease or COPD.

Obstructive Sleep Apnea Syndrome (OSAS) is a debilitating sleep and breathing disorder which can lead to numerous different afflictions sometimes resulting in stroke, heart attack or other ailments. Debilitating sleep and breathing disorder has been defined as the cessation of breathing for 10 seconds or more (an apnea) at least five times per hour of sleep. Apnea Hypopnea Index (AHI) is the average number of apnea intervals per hour. An AHI of 5 is considered very minimal, less than 15, mild, 30, moderate and over 30, severe.

It is known that the body and muscles relax which can cause excess tissue to collapse into the upper airway (back of the mouth, nose and throat) and block breathing. When breathing is interrupted by an obstruction in the airway, the body reacts by waking enough to start breathing again. These arousals may occur hundreds of times each night but do not fully awaken the patient, who remains unaware of the loud snoring, choking and gasping for air that are typically associated with Obstructive Sleep Apnea Syndrome. Obstructive Sleep Apnea sufferers never get “a good night of sleep” because repeated apneas and arousals deprive patients of REM and deep-stage sleep leading to chronic daytime exhaustion and long-term cardiovascular stress.

Obstructive Sleep Apnea has a profound impact on an individual's health. Excessive daytime sleepiness caused by disruption of normal sleep patterns leads to a significant increase in the rate of accidents for afflicted patients, including a seven fold increase in automobile accidents. Over the long term, Obstructive Sleep Apnea is associated with greater risk of hypertension and cardiovascular disease. The National Commission on Sleep Disorders Research estimates that 3800 cardiovascular deaths due to sleep apnea occur each year. In addition, loud snoring and intermittent breathing interruptions can affect the quality of sleep of the Obstructive Sleep Apnea patient's bed partner. Witnessing an apnea can be a frightening experience because the Obstructive Sleep Apnea patient appears to be suffocating.

24% of adult men and 9% of adult women, or more than 20 million Americans, are estimated to have some degree of Obstructive Sleep Apnea. Of these, six million are estimated to have cases severe enough to warrant immediate therapeutic intervention. However, Obstructive Sleep Apnea was not well understood or recognized by physicians until recently and only a fraction of these 20 million Obstructive Sleep Apnea patients have been diagnosed and treated by a physician. The number of patients currently undergoing treatment is probably on the order of one million.

Hypertension refers to elevated blood pressure and is a common disease, characterized by elevated systolic and/or diastolic blood pressure. Despite the prevalence of hypertension and its associated complications, control of the disease is somewhat inadequate. Only a third of the population suffering with hypertension control their blood pressure adequately. OSA, left untreated can lead to hypertension.

It is known that various forms of positive airway pressure during sleep can provide an effective form of therapy for apnea sufferers. Approaches taken have been to apply Continuous Positive Airway Pressure (CPAP) in which a positive pressure is maintained in the airway throughout the respiratory cycle or Bi Level Positive Airway Pressure (BiPAP) in which positive pressure is maintained during inspiration but reduced during expiration. Intermittent mechanical positive pressure ventilation can be provided where pressure is applied when an episode of apnea is sensed. Positive airway pressure devices have traditionally employed either a face mask to cover the patient's nose or nasal pillows as the interface between a ventilation device and the patient's airways. These interfaces suffer the shortcoming that they are sometimes cumbersome and uncomfortable to wear, often leading to rejection by the patient.

The face mask typically requires a harness, headband or other headgear to keep the mask in position, something patients frequently find uncomfortable, particularly when sleeping. Such face masks are constructed to seal against the patient's face and sometimes chafe against the patient's skin which may cause facial sores, particularly if the patient's sleep pattern involves movement and repositioning during the night. Further, the seal against the patient's face may leak thus reducing or eliminating the efficacy of the device.

Some face mask designs are intended to apply pressure to the sinus areas of the face adjacent the nose, causing the airways to narrow, thereby increasing the velocity of flow through the airway, but decreasing the pressure against the nasal mucosal walls. This process tends to strip moisture from the mucosal wall during inspiration thus drying the wall and producing a burning sensation. Consequently, many patients find the face mask uncomfortable, somewhat ineffective and often results in the patient discontinuing that therapy.

It has also been proposed to provide nasal pillows which are pressed against the interior portion of the nares to close the nostril openings. Nasal pillows require a robust headband or harness to maintain the pressure thus, often leading to discomfort similar to that suffered by use of the face masks.

Examples of nasal masks are shown in U.S. Pat. Nos. 5,335,654 and 5,535,739 to Rapoport which describes a CPAP system using a conventional nasal mask.

U.S. Pat. No. 4,782,832 to Trimble discloses nasal pillows held in a patient's nose by a harness arrangement and incorporating two accordion or bellows shaped nipples for fitting against the nostril openings.

U.S. Pat. Nos. 5,269,296; 5,477,852 and 5,687,715 to Landis describes CPAP devices for treatment of sleep apnea with relatively stiff or rigid nasal cannula surrounded by inflatable cuffs to retain the cannula in the pares.

It has been recognized that nasal Expiratory Positive Airway Pressure (EPAP) may tend to maintain the patient's airways open during sleep to treat apnea conditions. Different devices have been proposed in effort to provide EPAP, including elongated adhesive strips mounting in the central area a one way valve intended to be placed over the nostrils when retiring. The device is intended to allow the valve to open as a patient inhales but as the patient exhales, close the valve to create a back pressure in hopes of opening the airways to relieve snoring. Such devices, while appearing to offer relief in theory, suffer the shortcoming that the single valve is ineffective to properly control flow through both the patient's nostrils and testing shows that the adhesive strip is challenging to apply and maintain it in position during the sleep period.

CPAP is the preferred initial treatment for most people with Obstructive Sleep Apnea. With CPAP, patients wear a mask over the nose and/or mouth. An air-blower forces air into a mask and through the nose and/or mouth. The pressure is adjusted so that it is just enough to prevent the upper airway tissues from collapsing during sleep. The pressure is constant and continuous. CPAP prevents airway closure in use, but apnea episodes return when CPAP is stopped or is used improperly. Patients typically find such masks cumbersome, bulky, uncomfortable, noisy and in need of daily cleaning thus discouraging continuous use.

Other devices have been proposed such as mandibular appliances for patients with mild sleep apnea, dental appliances that prevent the tongue from blocking the throat and/or advance the lower jaw forward. These devices help keep the airway open during sleep.

In effort to avoid the discomfort of CPAP masks, it has also been proposed to provide individual nasal adhesive patches with individual one way valves to be adhered to the patient's nostrils to generate a back pressure upon exhaling. Such devices, while promising in theory, are not adequately affixed to the nostrils in such a manner such as to provide positive lodging in the nasal passage and to positively block flow upon exhaling.

Other efforts to avoid the dreaded CPAP machine proposes an exterior adhesive strip to be applied transversely across the patient's nose and configured with a spring like band to purportedly hold open and extend the nasal passages. Such devices fail to effectively address the issues of sleep apnea.

Chronic Obstructive Pulmonary Disease (COPD) includes chronic bronchitis, emphysema and asthma. In both chronic bronchitis and emphysema, air flow obstruction limits the patient's airflow during exhalation. COPD is a progressive disease characterized by a worsening base line respiratory status over the period of many years with sporadic exacerbations often requiring hospitalization. Early symptoms include increased sputum production and sporadic acute exacerbations characterized by increased cough, purulent sputum, wheezing and fever. Late in the course of the disease, the patient may develop hypercapnia, hypoxemia, cor pulmonale with right-sided heart failure and edema.

Pulmonary rehabilitation is frequently used to treat patients suffering from a variety of medical ailments such as those mentioned. For example, COPD patients are taught new breathing techniques that reduce hyperinflation of the lungs and relive expiratory airflow obstructions. Typically, these new breathing techniques include diaphragmatic and pursed-lip breathing. Pursed-lip breathing involves inhaling slowly through the nose and exhaling through pursed-lips (as if one were whistling), taking two or three times as long to exhale as to inhale. Most COPD patients instinctively learn how to perform pursed-lip breathing in order to relieve their dyspnea. It is believed that producing a proximal obstruction (e.g. pursing the lips) splits open the distal airways that have lost their tethering in certain diseased states.

It has been reported that pursed-lip breathing by COPD patients results in a reduction in respiratory rate and an increase in tidal volumes and an improvement of oxygen saturation. However, pursed-lip breathing requires conscious effort, thus the patient cannot breathe through the pursed lips while sleeping. As a result, the patient can still become hypoxic at night and may develop pulmonary hypertension and other sequelae as a result.

Non-invasive Positive Pressure Ventilation (NPPV) is another method of treating diseases that benefit from regulation of the patient's respiration. NPPV refers to ventilation delivered by a mask, nasal prongs, pillows or face mask. NPPV eliminates the need for intubation or tracheostomy.

NPPV can deliver a set pressure during each respiratory cycle, with the possibility of additional inspiratory pressure support in the case of bi-level devices. It is recognized that most patients experience difficulty adapting to nocturnal NPPV leading to poor compliance. Mask discomfort is a very common problem for patients new to NPPV, because the high pressure om the nose, mouth and face and because the tight straps are uncomfortable.

Both the pursed-lip breathing and the use of NPPV have been shown to offer significant clinical benefits to patients with a variety of medical illnesses including COPD, heart failure, pulmonary edema, sleep apnea and other sleep breathing disorders. Expiratory resistance is believed to provide the bulk of clinical improvements when using pursed-lip breathing and NPPV, through a variety of physiological mechanisms. For example, in COPD expiratory resistance is believed to facilitate expiration, increase tidal volume and decreases respiratory rate. Various devices have been proposed for applying positive pressure to the patient's nostrils and even for balancing flow between the two nostrils. See U.S. Pat. No. 5,740,799 to Nielsen.

It has been proposed to extend the expiratory time in effort to reduce the respiratory rate as by incorporating a flap valve in a nasal device for restricting exhalation flow and facilitating connection to an oxygen source. A device of this type is shown in U.S. Pat. No. 7,856,979 to Doshi. While proposing a degree of restriction during exhalation, Doshi fails to show a device and method of use to fully block exhalation so that a patient might benefit from his or her own biological responses to self-regulate during the inspiration/expiration cycle.

Other devices have been proposed for releasing oxygen only during inhalation. A device of this type is shown in U.S. Pat. No. 8,365,736 also to Doshi.

Other devices, such as ball valves have been proposed for interrupting oxygen supply during the patient's exhale phase. A device of this type is shown in U.S. Patent Application Publication No. 2008/0142012 to Fansworth.

It has been recognized that debris can build up in a valving arrangement of a face mask and that the consequent pressure build up can be relieved through a side vent of a control valve and an anti-asphyxia bypass feature. A device of this type is shown in U.S. Pat. No. 7,559,326 to Smith. Devices of this type, while tending to serve their intended purpose, suffer the shortcoming that some patients resist use of a mask covering a portion of the patient's face and the fact that failure to totally block exhalation fails to afford effective relief from a patient suffering from sleep apnea.

In unrelated art, tracheotomy valves have been proposed which include diaphragms spaced some distance from the end of the valve body for opening when a negative pressure has been applied. A device of this type is shown in U.S. Pat. No. 8,051,853 to Bare. To Applicant's knowledge, such devices have not been incorporated in sleep apnea nasal devices or sized or configured in such a way as to be so incorporated.

It is believed that at least some forms of sleep apnea may be treated by fully and completely blocking the patient's exhalation while allowing for free inhaling.

SUMMARY OF THE INVENTION

There thus remains a need for a device convenient for a patient to wear which will protectively and fully block the patient's exhalation without otherwise interfering with breathing.

The present invention includes nasal tube devices formed with a body for receipt in a patient's nasal passages and configured to be held in place. The body is configured with a passage surrounded by a proximally facing valve seat and a flexible membrane carried from the body to so the peripheral edges thereof will be carried away from the seat during inhaling but will seal against the seat during exhalation to fully block exhaling to thereby facilitate self-regulation of the patient's breathing and treat apnea.

The method of the present invention employs a nasal tube including a tubular body configured at the distal end with a rim forming a proximally facing circular seat. A circular membrane closes the passage during exhalation but on inspiration is shifted away from a seat to open communication through the nostril.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a nasal tube device embodying the present invention;

FIG. 2 is a top plan view of the device shown in FIG. 1;

FIG. 3 is a bottom plan view of the device shown in FIG. 1;

FIG. 4 is a transverse sectional view, in enlarged scale, taken along the lines 4-4 of FIG. 2;

FIG. 5 is a perspective exploded view, of the device shown in FIG. 1;

FIG. 6 is a broken side view, in reduced scale, of a pair of cannula devices shown in FIG. 1 and coupled together;

FIG. 7 is a broken bottom view of the device shown in FIG. 6;

FIG. 8 is a perspective view, in reduced scale, of the device shown in FIG. 1 connected to a patient by means of a band;

FIG. 9 is a broken bottom view similar to FIG. 7 but showing a second embodiment; and

FIG. 10 is a perspective view, in reduced scale, of the device of FIG. 9 mounted to a user's head.

FIG. 11 is a perspective view of a valve arrangement which may employed with the nasal device shown in FIG. 1;

FIG. 12 is an exploded view of the valve device shown in FIG. 11;

FIG. 13 is a transverse sectional view, in enlarged scale, taken along the line 13-13 of FIG. 11 and showing the valve in its closed position;

FIG. 14 is a vertical sectional view similar to FIG. 13 but depicted the valve in its open position; and

FIG. 15 is a vertical sectional view of the valve shown in FIG. 13 coupled to a nasal tube device similar to that shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one preferred embodiment, the present invention incorporates a pair of nasal tube devices including elongated tubular housings 21 capped at the distal end by a relatively rigid rim device 23 supported distended radially by means of radial ribs 25 and carrying a flexible membrane 27 centrally from a mounting post 29. The rim device 23 forms a proximally facing circular valve seat 31 (FIG. 4) such that when the patient inhales the diametrically opposite sections of the membrane 27 will be raised proximally off the seat 31 for the patient to inhale ambient air and, upon expiration, the membrane 27 will be driven distally to engage the peripheral edges with the seat 31 to positively block expiration of spent air. Preferably, the rim device 23 is constructed to dispose the membrane 31 in close space relationship with the end of the respective housing 21, preferably on the order of 3-6 mm from the end of such housing.

Obstructive Sleep Apnea (OSA), afflicts some 22 million Americans and a quarter of a billion people worldwide. Continuous Positive Airway Pressure (CPAP) is a recognized procedure for treating OSA and involves the application of pressure to a facemask or nasal insert such as by a pump, oxygen supply or the like to thereby apply positive pressure to the patient's nasal passage. I have discovered that certain types of sleep apnea can best be treated by harnessing the patient's own individual specific biological response to back-pressure during the exhalation of spent air. By blocking escape of air from the patient's nasal passages during the normal cycle of breathing (inspiration/expiration) the patient's own expiration pressure can be harnessed for treating sleep apnea. I refer to this procedure as the Nussbaum Nasal Auto Continuous Positive Air Pressure (NNA-CPAP). The present invention is directed to a device for carrying out thus treatment.

Referring to FIGS. 1, 6 and 8, in one of my preferred embodiments, I provide a pair of elongated tubular housings 21 to be inserted in the patient's nasal passages as shown in FIG. 8 to be frictionally held therein. The housings are connected together by means of an adjustable nose strap device, generally designated 41. The strap may be constructed of hook and pile connectors or possibly a belt device formed with bores spaced therealong for receipt of nubbins formed with a connector strap.

Referring to FIGS. 1, 3 and 6, the opposite sides of the respective housings 21 carry respective connector tabs, generally designated 45, incorporating hook and pile fasteners for connection to hook and pile fasteners formed on the proximate ends of respective connector straps, generally designated 51. The connector straps 51 are formed at their free extremities with hook and pile connectors 53 and 55 configured to connect together at the back of the patient's head as shown in FIG. 8.

The housings 21 are tubular shaped and formed with robust, through internal passages 61 (FIG. 5) and having their walls constructed at the proximal extremity 53 of pliable material such as a soft polymeric or elastomeric material, as for example, polypropylene or polyethylene to resistively conform to the shape of the specific patient's nasal passage to be held in place within the respective nostrils.

The walls at the distal extremity of the housings 21 may be formed of more rigid polymeric material to thus inherently maintain its circular shape so that the seat 31 could be formed in the body itself and held in a circular configuration against the pressure of the walls of the nasal passage for positive sealing with the cannular membrane. In one embodiment I form the housing with interior diametrical struts 65 for cooperating in holding the wall distended outwardly against the walls of the particular nostril to maintain a firm frictional engagement to hold the housing in place and prevent leakage between the interface of the nostril and exterior surface of the housing. It will be appreciated that the overall shape of the membrane should complement the shape of the seat.

Referring to FIG. 4, in this exemplary embodiment, the proximal extremity is undercut in its exterior to form a reduced-in-diameter short shell 67 terminating in a top annular edge 75. The proximal end of the undercut forms a radially outwardly opening gland 80 terminating in its proximal end in a distally facing annular shoulder 68.

The rim device 23 includes an annular barrel 71 formed internally with an annular flange 76 configured to set on the top edge 75 of the shell 67 and terminate in a radially inner circular edge 78 of the same diameter as the interior surface of the housing and disposed flush therewith. The barrel 71 is configured to on its proximal end with an interior diameter to form an interference fit with the exterior diameter of the shell 67 and projects upwardly therefrom to form an annular, inwardly opening gland 81 to receive the shell 67.

The membrane 27 is formed from a memory material and with an outside diameter to nest freely in the inner diameter of the housing and to clear the inside diameter defined by the annular edge 76 of the flange 75 for free movement of the periphery relative to the seat.

With continued reference to FIG. 4, the rim device includes a retainer device 26 constructed of a hard polymeric and is configured with the cruciform spokes 25 radiating outwardly from a central hub 85 having a bore therein for slip fit receipt of the female portion 87 of the fastener 29.

Referring to FIG. 5, the membrane 27 is configured centrally with a through bore 91 formed for receipt of a stem 93 of a male portion 95 of the fastener 29.

The retainer device 26 is further formed with an annular rim 86, FIG. 4, circumscribing the radially outer ends of the spokes and configured to be nested in the gland 81. The rim 86 is formed with a sufficient radial thickness to overhang the annular edge 76 of the flange 76 to cause the proximally facing annular surface thereof to form the proximally facing seat 31 against which the outer periphery of the membrane 27 will abut when drawn distally to the solid line position shown in FIG. 4 to seal evenly entirely about the periphery.

Referring to FIG. 5, the membrane 27 is configured centrally with a through bore 91 formed for receipt of a stem 93 of a male portion 95 of the fastener 29.

Referring to FIGS. 6, 7 and 8, it will be appreciated that the fastener straps 51 are sized to cooperate with the tubular housings 21 and connector tab device 41 to fit around the wearer's head as shown in FIG. 8 for the hook and pile fastener strips 53 and 55 to be fastened together at the back of the head to conveniently hold the nasal cannulae in place.

In operation, the patient suffering from obstructive apnea can easily don the sleep apnea device of the present invention by positioning the tubular housings 21 sufficiently far in the nasal passages (FIG. 8) to be held in place so that the adjustable fastener tabs 45 may be adjusted to accommodate the spaced apart positioning of such housings so that such housings will nest comfortably in the patient's nasal passages.

As the housings 21 are pressed into the nasal passages, the proximal portions 54 of the housing, being constructed of somewhat pliable material, will be compressed into a shape in accordance with the shape of the patient's nostrils to provide for comfortable setting thereof and prevent leakage around the peripheries.

Once the device has been fastened in position on the patient's head as shown in FIG. 8, the patient may breathe through his or her nose. Referring to FIGS. 1 and 8, when the patient inhales, the periphery on at least two diametrical sides of the membrane 27 will be drawn proximally away from the seat 31 against the memory position of such membrane to the broken line position shown in FIG. 4 to thereby allow free passage of air past the membrane.

The peripheral edges of the membrane will thus seat evenly around the periphery against the seat 31 to block flow of spent air from the patient. This then serves to, on each exhalation cycle, provide positive air pressure in accordance with the particular biological characteristics of the patient, i.e. size, weight, lung capacity and strength, lung volume and breathing cycle. The results are comparable to those of CPAP but without the necessity of applying external pressure, pump devices and face masks or paraphernalia.

With continued reference to FIG. 4, it will be appreciated that in this preferred embodiment, when the patient inhales, the membrane will bend proximally to cause the pressure differential across the membrane to flex the peripheral edges away from the seat 31 in umbrella fashion to allow for airflow past the seat and past the exterior peripheral edges of the membrane and through the respective tubular devices. Then, upon exhalation, the pressure differential across the membrane, in combination with the memory of the membrane itself, will cause the peripheral edges of the membrane to be driven distally to engage the seat 31 entirely around the periphery to thereby positively and fully stop exhalation and allow the pressure to build up in the patient's air passages and lungs.

In some embodiments I incorporate different configurations for my fasteners to hold the device in place on the patient's head. For instance, as shown in FIG. 10, I incorporate flexible resilient ear pieces 101 and 103 which curve upwardly and rearwardly to form respective hooks 105 on the free extremities thereof to hook under and around the patient's ear, not unlike an inverted ear piece of conventional eyeglasses.

A second preferred embodiment of the head mounted sleep apnea device of the present invention is shown in FIGS. 11-13. This device incorporates a nasal tubular housing, generally designated 101, (FIG. 15) similar to the housings 21 and configured to mount valve devices 103 at the distal extremities thereof. While only a single housing is shown, as will be apparent to those of skill, a device typically includes a pair of housings similar to the housings 21. The housing 101 is formed internally with flexible, diametrical struts 105 to lend some support against total collapse but cooperating to provide for flexibility of housing walls to accommodate the shape of the patient's nasal passages and to maintain distension thereof to maintain functional engagement with the walls of the nostril.

The wall of the housing 101 is formed in the exterior of the proximal end with an annular undercut 107 defining a cylindrical shell 113 configured at its proximal end with a distally facing annular shoulder 109. The shell device terminates at its distal end in a distally facing end 114. The valve device includes a cage 102 constructed of a hard polymeric and mounted to a rim device, generally designated 104, configured with a short cylindrical barrel 116 received within the gland defined by the undercut 107 to abut the shoulder 109. The barrel is configured interiorly with an annular rib 115 constructed to abut the distal end 114.

The cage is formed with close spaced proximal and distal walls, the proximal wall including an annular ring 121, received concentrically in the shell barrel 116 and the distal wall formed by a retainer ring device, generally designated 135, cooperating to cage a membrane 131 to float proximally and distally with the patient's normal breathing. The ring 121 is configured with a proximally facing, internal, annular gland 125 configured with a proximally facing annular shoulder 127 (FIG. 15).

Formed integrally with the ring 121 is a network of relatively rigid radial spokes 129. In this preferred embodiment, I show four cruciform shaped spokes 129. In practice, the number of spokes are selected in accordance with the deign parameters of the artisan and typically incorporate a network of eight radially projecting spokes to provide support for the flexible membrane.

A retainer ring device 137 is received in the gland 125 to abut the shoulder 127 and is formed on its proximal side with a proximally facing annular seat 141 configured to mate with and support the peripheral circular edge of the membrane 131 when the patient exhales as shown in FIG. 13. The ring device 137 is formed with a plurality of spokes 139 to contain the membrane.

In this embodiment the space between the facing surfaces of the walls defined by the spokes 129 and 139 is 0.3 mm but may have a greater thickness, as for instance about 0.5 to about 1.0 mm. to allow room for working of the membrane without folding or wrinkling thereof. It is understood that this cage space may vary, it only be important that the membrane 131 be contained for a rapid response to the patient's breathing and to restrict movement which might cause the peripheral edges to move out of alignment with the seat 141.

In one embodiment the membrane 131 is constructed of flexible polymeric material having a memory and sufficient body to be self-supporting but sufficiently light to be floated about in response to the patient's breathing. It is constructed with a diameter smaller than the interior of the diameter of the rim 121 for flow of atmospheric air between such interior diameter and the outside diameter of such membrane shown in FIG. 14.

As noted, the membrane 131 is relatively thin and constructed with a minimal mass such that when the patient inhales, as shown in FIG. 14, the pressure differential across the membrane will readily lift the membrane off the seat 141 with minimal resistance thus presenting little or no interference with the inhalation by the patient but yet serving to positively seal about its periphery to the seat 141. In some embodiments the membrane is constructed with a rigid body to float about the cage without flexing.

In operation, a patient suffering from sleep apnea may be treated with the sleep apnea device of FIGS. 11-15. The patient may merely place the tubular housings 101 in his or her nasal passages, it being appreciated that the housing wall, struts 105, rim device 104 and spokes 129 and 139 will flex sufficiently to allow the housing to flex slightly to accommodate the transverse cross sectional shape of the patient's nasal passages. In practice, for some embodiments, I construct the membrane and seat such that any flexing of such seat out-of-round will be accommodated by the clearance between the outside diameter of the membrane and the inside diameter of the ring 121 without interfering with movement of the membrane under influence of the patient's inhaling and exhaling. In other embodiments, I construct the spokes 129 and 139 and the housing wall and rings to resist radial flexing to thus positively maintain the circular configuration for the seat 141 as the device is inserted in the patient's nasal passage.

In practice, I construct the membrane 131 with an external diameter sized to cause the peripheral edges to clear between the interior diameter of the ring 121, as well as to overlap the seat 141 such that flexing of the wall of the housing 101 and the rings 113 and 121 to an out-of-round position, say providing an eccentric configuration of 2-3 mm from the round, so the interior diameter of the ring 121 will not interfere with free travel of the membrane under influence of the patient inhaling and exhaling. Thus, with the light feather-like weight of the membrane 131 and such freedom of movement, the membrane will float freely proximally and distally with respect to the seat 141 so as to provide minimal interference with the patient's normal inhaling so as to avoid any discomfort during the inhaling cycle.

Once the housings 101 are inserted proximally in the patient's nasal passages, and a band, similar to that shown in FIG. 8, extended around the patient's head to hold the housings in place, the patient is at liberty to sleep in the normal fashion, maybe with his or her bed-partner without concern over him or herself being awakened by sleep apnea or snoring which might interfere with the bed-partner's sleep.

That is, when the patient inhales, the pressure differential across the membrane 131 as shown in FIG. 13 will lift the membrane off the seat 141 to allow the patient to draw atmospheric air into the lungs without interference.

During the exhaling cycle, however, the pressure differential across the membrane 131 will drive such membrane distally to engage the peripheral edges thereof evenly entirely around the periphery of the seat 141 to fully block exhaling by the patient. It has been found that this feature of the present invention effectively serves to treat the patient's sleep apnea without excessive interference with the patient's sleep pattern but yet in most cases provides for an uninterrupted sleep period.

With my nasal CPAP Functional Residual Capacity (FRC) will be optimized during the expiratory, as well as the inspiratory cycles. This will improve the Ventilation/Perfusion (dv/dt/dq/dt) relationships and therefore maintain adequate oxygenation where Ventilation=Air Flow=Volume of air time unit=dv/dt and Perfusion=Blood Flow=Volume of capillary blood per unit of time−dq/dt. CO₂ elimination is not impaired by the level of CPAP generated by this device, as CPAP values at the target range do not impair levels of expired Carbon Dioxide, called end-Tidal CO₂(ETCO₂) nor does it impair the partial pressure of Carbon Dioxide in the blood (PCO₂).

As will be appreciated by those of skill, my device is intended to present resistance to air flow. Resistance is calculated as the driving pressure divided by air-flow. Simply stated, if pressure is P and flow is dv/dt (flow=volume of air per unit time) then Resistance is calculated as P/dv/dt or R=driving pressure/airflow presented in units of cm H₂O/L/sec. Since my CPAP generates pressure in the range of 4-10 cm H₂O (or between 40 and 10 mm H₂O) during the expiratory phase (expiration). The total pressure may be calculated by applying such pressure to a surface area with approximately 5 mm radius of nasal opening (surface area SA=3.14×5×5=78.5 mm²=0.1256 SI) (square inch SI=625 mm²) represents maximum 10/0.1256=79.61 mm H₂O/SI=0.11 PSI

However, it should be noted that the nasal resistance represents 50% of total airway resistance and that airway resistance changes with lung volume, but not in a linear fashion. Increasing lung volume above FRC (Functional Residual Capacity) only minimally decreases airway resistance hence my nasal CPAP will maintain adequate pressure keeping the airway passages open during the entire respiratory cycle (inspiration and expiration). In very low lung volumes R may become higher. As will be recognized by those of skill, R also depends on acceleration (inertance) and frictional factors.

From the foregoing it will be appreciated that my discovery of a method for treating sleep apnea and a device for practicing that method provides an effective and convenient apparatus for the patient to wear without the hindrance normally associated with masks and related paraphernalia such as pressurization devices and the like.

In essence my device and procedure is directed more at the CPAP values (Pressure values) and not so much at the Resistance which can be manipulated by volume and flow variations. My nasal CPAP can be adjusted by the patient's individual lung volumes and flow, and since my device provides a positive seal, it guarantees an effective CPAP.

Although the present invention has been described in detail with regard to the preferred embodiments and drawings thereof, it should be apparent to those of ordinary skill in the art that various adaptations and modifications of the present invention may be accomplished without departing from the spirit and the scope of the invention. Accordingly, it is to be understood that the detailed description and the accompanying drawings as set forth hereinabove are not intended to limit the breadth of the present invention. 

1. Head mounted nasal respiratory apparatus comprising: a pair of nasal tube devices configured with respective tubular bodies for receipt in a patient's nasal passages, the bodies configured with through air-flow passages and formed with respective proximal and distal extremities, the bodies including respective rim devices formed with respective proximally facing valve seats; respective membranes having marginal edges configured to be, when the devices are disposed in the nasal passages, responsive to the pressure differential generated by the patient inhaling to be shifted from respective open positions off the respective seats to provide for air flow through the air-flow passages and further responsive to the patient exhaling to close the marginal edges on the respective seats to fully block exhaling from the respective nasal passages; and mounting devices carried from the respective tube devices to mount the respective membranes for shifting from the respective open to the closed positions.
 2. The respiratory apparatus of claim 1 wherein: the mounting devices include cages mounted from the tube devices and constructed with proximal and distal walls to contain the membrane in floating relationship over the seat.
 3. The respiratory apparatus of claim 2 wherein: the membranes are constructed to, when lifted off the respective seats, accommodate airflow around the peripheries thereof.
 4. The respiratory apparatus of claim 2 wherein: the cage devices are configured with proximal and distal walls formed with through flow openings.
 5. The respiratory apparatus of claim 4 wherein: the proximal and distal walls are formed by radially projecting spokes.
 6. The respiratory apparatus of claim 4 wherein: the walls of the respective cage devices are disposed in respective planes and spaced apart a distance no greater than 0.3 mm.
 7. The respiratory apparatus of claim 1 wherein: the membranes are flexible.
 8. The respiratory apparatus of claim 1 wherein: the membrane is constructed of memory material.
 9. The respiratory device of claim 1 wherein: the respective seats are circular; and the membranes are circular to define circular peripheral edges and the membranes constructed to be responsive to the pressure differential to seal the entire extent of the peripheral edges against the respective seats.
 10. The respiratory device of claim 1 wherein: the membranes are so constructed that a differential pressure thereacross of substantially 0.11 psi will move the respective diaphragm relative to the valve seats.
 11. A method of treating sleep apnea including: inserting nasal flow control devices in the nasal passages of a patient; and fully blocking airflow from the nasal passage during the exhalation cycle.
 12. The method of claim 11 that includes: floating membranes off respective valve seats during the inhalation cycle and applying the peripheral edges of the membranes to the seats during the exhalation cycle.
 13. The method of claim 13 that includes: caging the membranes in cages configured with the seats.
 14. The method of claim 13 that includes: anchoring the membranes centrally to the respective flow control devices.
 15. The method of claim 13 that includes: applying the peripheral edges of the membrane entirely around the seal.
 16. A respiratory apparatus comprising: at least one flow control device for insertion into a patient's nasal passage, formed with a through flow passage and a proximally facing seat; and means responsive to the patient's exhalation to contact the seat and totally block flow through the passage. 